Question on whether to retake GMAT

I've just taken the gmat and I got a 680 (79 percentile for both verbal and math). I'm looking to apply to the top 10 schools and was wondering whether or not to retake the test. I went to undergrad at Carnegie Mellon (BS in Biology/Biomedical Eng) and had a lower GPA ~2.5 overall, 3.0 for my last t...